Rubio’s campaign stop and the emphasis on seniors and retirees — who make up a significant portion of the voting population in Florida’s 13th district, one of the oldest in the nation — came as Jolly faced renewed attacks from a Democratic outside group focused on his career as a lobbyist.

The new ad, from House Majority PAC, charges that Jolly “lobbied for a special interest that wanted to privatize Social Security,” a proposal that opponents say would reduce benefits and undermine the solvency of the program.

Jolly has said he didn’t lobby on Social Security, and that he was simply “overcomplying” with disclosure requirements because the issue came up briefly in conversations with Ryan.

The attack is the latest in a volley from outside groups affiliated with both parties meant to sway a race that both public and private polling has shown to be close.

Though the district became more competitive for Democrats with former Rep. Bill Young’s (R-Fla.) passing, the unpopularity of ObamaCare and the president himself in the district make it a tough fight for Sink.

The stakes are high for Democrats, however — the race is seen by many as a bellwether of what the party can expect come November.